1987 Chiba earthquake
1987 CE.
Shown on the map at 35.375°, 140.493°.
The 1987 Chiba Prefecture offshore earthquake (Japanese: 千葉県東方沖地震) occurred off the east coast of the Boso Peninsula in Chiba Prefecture at 11:08:01 JST on December 17, 1987.
Text from the Wikipedia article 1987 Chiba earthquake, licensed CC BY-SA 4.0.